原子吸收光谱法测定蔬菜中的铁、锰、铜、铅和镉

采用硝酸-高氯酸消解蔬菜样品,火焰原子吸收光谱法测定蔬菜中铁、锰和铜,石墨炉原子吸收光谱法测定蔬菜中的铅和镉。对仪器的工作条件作了探讨。在最佳实验条件下对韭菜、芹菜、洋白菜3种蔬菜进行测定,含量分别为铁：20.01、4.57、5.60μg.g-1,锰：1.445、1.141、1.204μg.g-1,铜：1.031、0.566、0.328μg.g-1,铅：0.106、0.085、0.076μg.g-1和镉：0.012、0.032、0.018μg.g-1。加标回收率为94.0%—106%。该方法简便、准确。     

光谱法研究人发、指甲中锰、镍含量变化曲线的特征

在近10年内按季度收集了同一个人的头发样品33份和指甲样品41份,应用火焰原子吸收光谱法测定了人发和指甲中的锰和镍含量.并分别绘制了锰和镍随时间(年)变化曲线.获得锰含量波动范围:人发中0.2100-1.500μg/g、指甲中0.8300-2.391μg/g;镍含量波动范围:人发中0.4900-1.750μg/g、指甲中1.179-4.184μg/g.含量变化曲线均具有非线性特征.     

ICP-AES同时测定涂料中镉、铬、钴和铅

系统研究了样品灰化条件对涂料中重金属元素测定结果的影响 ,建立了 ICP- AES法同时测定涂料中镉、铬、钴、铅元素含量的方法 ,方法的线性范围为 5— 10 0 0μg/ g,检出限为 0 .1— 0 .99μg/ g,相对标准偏差为 1.5 %— 9.9% (n=7) ,加入回收率为 97.0 %— 10 1.0 %。     

野猪肉和家猪肉中Ca、Cu、Fe和Zn的测定及比较

用硝酸、高氯酸混合酸消解样品,采用原子吸收光谱法,测定了野猪肉和家猪肉中的钙、铜、锌、铁的含量,并对其结果进行了分析.各元素在实验范围内,线性关系良好,回收率在98%-102%之间.野猪肉和家猪肉中钙含量分别为5.02μg·g-1和5.01μg·g-1,没有差异;而野猪肉和家猪肉中的Zn、Fe、Cu分别为39.95μg·g-1、27.50μg·g-1、13.62μg·g-1和9.53μg·g-1、Fe10.21μg·g-1、Cu 8.52μg·g-1;显著高于家猪肉.测定结果显示野猪肉含有丰富的Zn、Fe、Cu元素,具有较高的营养和保健价值,应合理开发利用野猪资源.     

石墨炉原子吸收法测定掺质钆镓石榴石中钴、铬、镍

用石墨炉原子吸收法测定掺质钆镓石榴石单晶中钴、铬、镍的含量,晶体中的钆不影响测定,但镓呈现背景干扰,文中对此进行了讨论。用氘灯扣除背景。钴、铬、镍含量为0.015%、0.037%、0.0057%时,变动系数分别为1.4%、1.9%、2.7%,检出限分别为2.5μg/g、0.87μg/g、2.0μg/g。     

FAAS测定垃圾渗滤液中的铜、铅、锌、铬、镉和镍

建立了火焰原子吸收光谱法测定垃圾渗滤液中铜、铅、锌、铬、镉和镍含量的方法.铜、镉、铬在0.01-0.05μg/mL呈现良好的线性关系,锌、镍、铅的线性范围为0.10-0.50μg/mL,相关系数分别为0.9987、0.9968、0.9993、0.9999、0.9995、0.9974.铜、铅、锌、铬、镉、镍的加标回收率范...     

微波消解-电感耦合等离子-质谱法测定船用燃料油中钒、铝、钙、锌、镍、钠、铁和硅

船用燃料油样品经微波消解后,采用电感耦合等离子-质谱法(ICP-MS)测定其中的钒、铝、钙、锌、镍、钠、铁和硅含量。方法在0—100μg/L范围内线性良好,仪器检出限为0.005—12.89μg/L,其回收率在90.39%—107.48%之间,相对标准偏差小于2.0%。本方法具有检出限低、准确度高、精密度好和多种元素同时测定等优点,完全满足船用燃料油实际样品的测试需要。     

原子吸收光谱法测定中药厚朴中的铜、铁和钙

用硝酸-高氯酸（4∶1）混合液对厚朴进行消解,然后采用原子吸收光谱法测定厚朴中铜、铁、钙的含量.结果表明,厚朴中含铜4.41μμg/g,含铁55.5 μg/g,含钙6872.5μg/g,加标回收率在93.6％-100.1％之间.该方法测定中药中金属离子的含量方法简便、快速、灵敏.该结果可为进一步研究厚朴的相关药理作用提供参考依据.     

ICP发射光谱法测定矿物、岩石中钡、锶

本法采用氢氧化钠、碳酸钠分解法,在5%盐酸溶液中,用电成耦合高频等离子体发射光谱测定矿物、岩石中钡、锶。方法分析灵敏度:钡为0.02μg/ml、锶为0.005μg/ml。相对均方误差:钡±2.0%,锶±2.0%。     

顺序注射氢化物发生-原子荧光光谱法测定化肥中砷、汞、锑和硒

本文建立了一种顺序注射氢化物发生 -原子荧光光谱法测定化肥中 As、Hg、Sb、Se含量的方法。在最佳条件下 ,As、Hg、Sb和 Se的检出限分别为 0 .1 5μg/ L、0 .0 6 1μg/ L、0 .0 4 6μg/ L、0 .2 5μg/ L。测定化肥中 As、Hg、Sb和 Se,回收率均在 94 .6 7%— 1 0 6 .81 %之间。该方法用于检测化肥中 As、Hg、Sb和 Se具有很好的可行性和实用性。     

微波消解-火焰原子吸收光谱法测定彝药毒清药中微量元素

建立火焰原子吸收光谱法测定＂毒清药＂中钙、镁、铁、锌、铜、锰元素含量的方法。用浓硝酸微波消解样品,采用校准曲线法测定。结果显示毒清药中含有Ca9.07mg/g,Mg3.56mg/g,Fe2.11mg/g,Zn0.070mg/g,Cu0.022mg/g,Mn0.61mg/g。RSD为3.1%—9.6%,回收率为94%—105%。此方法简单、准确,结果令人满意。     

Fractionalization, topological order, and quasiparticle statistics

We argue, based on general principles, that topological order is essential to realize fractionalization in gapped insulating phases in dimensions d > or = 2. In d = 2 with genus g, we derive the existence of the minimum topological degeneracy q(g) if the charge is fractionalized in units of 1/q, irrespective of microscopic model or effective theory. Furthermore, if the quasiparticle is either boson or fermion, it must be at least q(2g).     

Pressure, temperature, and thickness dependence of CO2-induced devitrification of polymer films

The glass transition temperature is known to increase with decreasing film thickness h for sufficiently thin poly(methyl methacrylate) films supported by silicon oxide substrates. We show that this system undergoes a CO2 pressure-induced devitrification transition, P(g), which is film thickness dependent, P(g)(h)=DeltaP(g)+P(bulk)(g). P(bulk)(g) is the bulk glass transition and DeltaP(g) can be positive or negative depending on T and P. The phenomenon of retrograde vitrification, wherein the polymer exhibits a rubbery-to-glassy-to-rubbery transition upon changing temperature isobarically, is also shown to occur in this system and it is film thickness dependent.     

Analytical model of nonlinear, single-mode, classical Rayleigh-Taylor instability at arbitrary Atwood numbers

An analytical model of the nonlinear bubble evolution of single-mode, classical Rayleigh-Taylor instability at arbitrary Atwood numbers (A(T)) is presented. The model is based on an extension of Layzer's theory [Astrophys. J. 122, 1 (1955)] previously applied only to the fluid-vacuum interfaces (A(T) = 1). The model provides a continuous bubble evolution from the earlier exponential growth to the nonlinear regime when the bubble velocity saturates at U(b) = square root of [2A(T)/(1+A(T)) (g/C(g)k)], where k is the perturbation wave number, g is the interface acceleration, and C(g) = 3 and C(g) = 1 for the two-dimensional and three-dimensional geometries, respectively.     

Iron in Parkinson disease, blood diseases, malaria and ferritin

The concentration of iron in Substantia nigra, the part of the brain which is involved in Parkinson disease, has been found by Mössbauer spectroscopy (MS) to be ~ 160 μg/g wet tissue and ~ 670 μg/g dry weight, both in control and Parkinson samples. All the iron observed by MS in these samples is ferritin-like iron. In several blood diseases, large amounts of ferritin-like iron have been observed in red blood cells. Desferral removed iron from serum, but not from red blood cells. The iron compound in the malarial pigment of human blood infected by P. falciparum was found to be hemin-like, whereas the pigment iron in rats infected by P. berghei was different from any known iron porphyrin.     

Causality,localizability, and holomorphically convex hulls

A generalization of local commutativity to the fields with an exponential momentum-space growth e ^lp is considered. To study the local properties of such fields we associate to each space-time region a topology ( ) on the test function space. It is shown that under any choice of the topology the fields of exponential growth are localizable only in space-time regions large in comparison withl. This happens because not any domain in the space of several complex variables is a domain of holomorphy. However, by specifying the topology through the use of holomorphically convex domains in ⁴, one can attach certain meaning to local commutativity for arbitrarily close spacelike separated regions of ⁴.     

Structural relaxations,phonons, and Ising models

Lattice models such as Ising or Potts models are very often successfully applied to order-disorder phenomena in solids (e.g., for alloys) or on surfaces (e.g., for physisorption). In this contribution it is shown how to derive such models from a microscopic Hamiltonian in the framework of classical statistical mechanics. Both structural relaxations and thermal fluctuations can be incorporated within the (temperature-dependent) parameters of the lattice model.